• Title/Summary/Keyword: Flexible

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Design and Numerical Analysis of Flexible Wing for Gust Response Alleviation (유연 날개 설계 및 돌풍응답완화 수치해석)

  • Lee, Sang-Wook;Kim, Tae-Uk;Kim, Sung-Chan;Hwang, In-Hee;Ha, Chul-Keun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.203-206
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    • 2006
  • In this study, the method of designing the flexible wing model which will be used for wind tunnel testing of gust response alleviation system was presented. The design concept proposed herein was validated by performing the modal testing of the flexible wing model manufactured for demonstration purpose. In addition, the study on the gust response alleviation using flexible wing control surface was performed. For this purpose, optimal control with output feedback was adopted for designing the control surface controller, and the effects of gust response alleviation was validated by performing the numerical simulation for the representative flexible wing model. The methods proposed and validated in this study can be applied for wind tunnel testing of the flexible wing for gust response alleviation.

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Vibration Analysis of the Shaft-duplicate Disk System (축-이중 원판계의 진동해석)

  • Chun, Sang-Bok;Lee, Chong-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.6
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    • pp.896-906
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    • 1997
  • The effect of duplicate flexible disks on the vibrational modes of a flexible rotor system is investigated by using an anlytical method based on the assumed modes method. The rotor model to be analyzed consists of duplicate disks on a flexible shaft. In modeling the system, centrifugal stiffening and disk flexibility effects are taken into account. To demonstrate the effectiveness of the method, a hard disk drive spindle system commonly used in personal computers and a simple flexible rotor system with two disks are selected as examples. In particular, the dynamic coupling between the vibrational modes of the shaft and the duplicate disks is investigated with the shaft rotational speed varied.

A Design Suggestion for Flexible Livingroom Cabinets at Apartment (가변성을 적용한 아파트 거실장식장 디자인 제안)

  • Jang, Ji-Hyen;Kim, Mi-Hee
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2007.11a
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    • pp.202-205
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    • 2007
  • With regal extension of balcony, the flexible design to remodel interior space of apartment has appeared as a new trend. But this desire of residents is allowed partially because of lack of flexible furniture design. So this study proposed to design for flexible livingroom cabinets at 30 pyong apartment according to life styles and furniture uses. To satisfy the storage and decoration of livingroom cabinets, it focuses on diverse decorative demands as well as practical functionality. And it suggests the applications of flexible factors; opening and closing, extension and reducing, assembling and dismantling, rotation and transfer according to 3 types like child-centered, hobby-centered, couple-centered family.

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Nonlinear Coupling Factor in Dynamic Model of Flexible Manipulator (유연 매니퓰레이터 동역학 모델링의 비선형 커플링 요소)

  • Lee Jin-Ho;Rhim Sung-Soo;Lee Soon-Geul
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.404-408
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    • 2005
  • Having flexibility in a manipulator will degrade trajectory tracking control and manipulator tip positioning. In practice, however, constraints imposed by various operating requirements, will render the presence of such flexibility unavoidable. The dynamic analysis of the flexible manipulator is essential in designing proper control systems. A flexible manipulator consists of infinite number of elastic modes and the modes are usually coupled to each other. For the practicality, however, it is usually assumed that the flexible system consists of finite number of elastic modes and the modes are decoupled. These assumptions result in a linear and decoupled mathematical model of the flexible manipulator and simplify the analysis of the dynamic behavior and the design of the control system. The decoupling and linearization of the flexible link, however, has been assumed without in depth analysis. This paper focuses on the analysis of the significance of the non-linear coupling factors.

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Influence of torsional rigidity of flexible appendages on the dynamics of spacecrafts

  • Chiba, Masakatsu;Magata, Hidetake
    • Coupled systems mechanics
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    • v.8 no.1
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    • pp.19-38
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    • 2019
  • The influence of torsional rigidity of hinged flexible appendage on the linear dynamics of flexible spacecrafts with liquid on board was analyzed by considering the spacecraft's main body as a rigid tank, its flexible appendages as two elastically supported elastic beams, and the onboard liquid as an ideal liquid. The meniscus of the liquid free surface due to surface tension was considered. Using the Lagrangian of the spacecraft's main body (rigid tank), onboard liquid, and two beams (flexible appendages) in addition to assuming the system moved symmetrically, the coupled system frequency equations were obtained by applying the Rayleigh-Ritz method. The influence of the torsional rigidity of the flexible appendages on the spacecraft's coupled vibration characteristics was primary focus of investigation. It was found that coupled vibration modes especially that of appendage considerably changed with torsion spring parameter ${\kappa}_t$ of the flexible appendage. In addition, variation of the main body displacement with system parameters was investigated.

Design of fuzzy logic controller using genetic algorithms for the flexible manipulator (Flexible manipulator를 위한 유전 알고리즘을 이용한 퍼지 제어기 설계)

  • 허남건;이기성
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1808-1811
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    • 1997
  • A position control algorithm for a flexible manipulato is stuudied. The proposed algorithm is based on a fuzzy theroy with a Steady State Genetic Algorithm(SSGA). The conventional fuzzy methods need expert's knowledges or human experiences. The SSGA, which is one of the optimization algorithms, tunes automatically the input-output membership parameters and fuzzy rules. The computer simulation is presented ot illustrate the approaches. Finally we applied a fuzzy theory with a SSGA to aposition control of a flexible manipulator.

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Design and control of two-link flexible manipulators (2개의 유연한 링크를 갖는 매니퓰레이터의 설계 및 제어)

  • 정주노;정완균;염영일
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.383-386
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    • 1996
  • In this paper, we propose a design method and control law for plannar type two-link flexible manipulator. In designing flexible links, we use Rayleigh's principle. To control flexible manipulator, input distribution controller is used, which is primarily on the basis of nonlinear variable structure control(VSC). The simulation results are also shown.

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Fabrication of Flexible Thin Film Diode Devices for Plastics film LCO (플라스틱 필름 LCD용 연성 박막 다이오드 소자 제작)

  • 이찬재;홍성제;한정인;김원근
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.218-221
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    • 2002
  • We have successfully developed the high performance flexible thin film diode device for flexible plastic film LCD. For flexible LCD, TFD device must be normally operated under any deformation state. Two type devices, Ti/Ta$_2$O$\sub$5//Ta and Al/Ta$_2$O$\sub$5//Al were fabricated and the symmetry and reliability of those were estimated under various measurement conditions including severely bending states.

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Robust Control Design for Robots with Flexible Joint and Link

  • Jung, Eui-Jin;Ha, In-Chul;Kim, Chang-Gyul;Han, Myung-Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.113.5-113
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    • 2001
  • In this work, we consider the flexible manipulator system. Generally, the manipulator system may often be made on the base of the imperfect modeling, joint friction, payload change, and external disturbances. These elements are uncertain factors. These uncertainties and flexibility make difficult to control the system. To overcome these defects, a class of robust control law is proposed for the flexible manipulator system and the singular perturbation approach is applied. To show the effectiveness of this control law, simulation is presented for one degree of freedom flexible joint and flexible link system.

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Recent Advance of Flexible Organic Memory Device

  • Kim, Jaeyong;Hung, Tran Quang;Kim, Choongik
    • Journal of Semiconductor Engineering
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    • v.1 no.1
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    • pp.38-45
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    • 2020
  • With the recent emergence of foldable electronic devices, interest in flexible organic memory is significantly growing. There are three types of flexible organic memory that have been researched so far: floating-gate (FG) memory, ferroelectric field-effect-transistor (FeFET) memory, and resistive memory. Herein, performance parameters and operation mechanisms of each type of memory device are introduced, along with a brief summarization of recent research progress in flexible organic memory.